Multiple Clematis in One Spot?

(Question)

Hello from Toronto’s East end ( Riverdale ISH area). I have a very sunny yard, sloping southwards and sandy soil…
I have had a Dutchman’s Pipe and I am taking it out as the roots are creeping all over the yard.
I have the crazy idea of growing 3 clematis to climb on my south fence ( which is really only a railing height).
I would love to plant them so they can somewhat intertwine and hopefully have a longer and more varied blooming period from it. ( I do not want to spread them out too much and the whole purpose of the railing versus fence is to allow the neighbours down the hill to see the garden as much as possible)… in an ideal world I would do either 3 white ones with different kind of blooms or 3 slightly different darker one of the same colour… is this just too crazy?
And I guess they would have to be of the same “type” to simplify pruning…?
Any advice would be appreciated Thanks
ps I am open to growing the in containers if that would give them better soil..

If the pic loaded the Dutchman’s pipe is what you see on the bottom right covering the top of the fence.

 

(Answer)

 

Hello and thank you for contacting the Toronto Master Gardeners.  Going by your photograph you already have a beautiful garden, and your idea of planting Clematis along the fence will certainly add to this lovely picture.

It’s a wonderful idea to plant more that one type of Clematis, by doing so you can introduce exciting colour combinations and extend the flowering period by having early, mid and late blooming varieties.  The very early blooming plants must be pruned in mid summer, where as the large flowered (Class 2) and later summer bloomers (Class 3) can both be pruned in early spring; so, these might be the best choices to avoid “pruning confusion”.  A quick note about pruning; don’t despair if you miss the appropriate pruning window as no permanent damage will come from forgetting or pruning at the wrong time.

I was unsure by your message if you intend to plant all three Clematis in the same hole, if so I would be cautious.  As your plants mature the root ball will become enormous and will quickly deplete the available nutrients.  Also, care must be taken to give the plants adequate airflow as crowding may encourage powdery mildew.  Typically, we recommend 24” between plants.  Having said that, it is possible to put two plants together if you properly prepare a generous hole at least 2 feet away from a fence and at least 5 inches deeper than the container they arrive in.  Place well rotted manure, compost and rich loam in the bottom of the hole along with some grit for drainage and a few handfuls of bone meal (or similar) fertilizer. Clematis do not like to be too hot, so ensure that their roots are cool by strategically placing leafy perennials, pebbles or mulching heavily around the roots.

Patience on your part will be necessary as your Clematis will take a few years to give you that wonderful show you are hoping for.  As difficult as it is, you will get better results in the long run if you immediately pinch out the growing tips of your new plants.  Below is a recommendation from the British Clematis society that details how proper pruning will encourage your new plants to produce multiple stems.

“Prune down to lowest pair of growth buds in early March and pinch out the growing tip on each new shoot as soon as it makes two pairs of leaves. Pinch out again when the shoots from these new leaves have also made two pairs of leaves. If growth also starts again from ground level, this too can be pinched out at same two pairs of leaves. This process can be repeated as often as you wish until mid-May, by which time your plant will already have many branching stems instead of just one or two. Pinching out will obviously delay the start of flowering, but now you will have blooms much lower on the plant and no bare expanse of stem.”

Note that in Toronto, you will want to wait until late spring to start the pinching process since you need to be able to see the actively developing buds and leaves.

Growing your Clematis in containers is also possible, we typically suggest choosing smaller varieties for containers, thus you may not get the fence coverage you are looking for with one of these types.  If you do choose to plant in containers, do ensure that you plant in as large a container as possible with extra mulch for winter protection as well as moisture retention.   Also ensure your container has adequate drainage, as Clematis roots are subject to root rot.

I hope is this helpful to you, and I wish you all the best with your Clematis project!